Blueberry Lime Recipe

Preheat and prepare pan

Preheat oven to 180°C (350°F). Line an 8–9 inch (20–23 cm) round cake pan or tart ring with parchment and lightly butter the sides.

Whisk eggs and sugar: In a clean mixing bowl, whisk the eggs and granulated sugar together over a double boiler (or use an electric mixer) until warm to the touch and sugar is dissolved. If using a stand mixer or handheld, beat until ribbon stage — the mixture should be pale, thick and tripled in volume (about 6–8 minutes with a mixer).

Fold dry ingredients: Sift together flour, baking powder and salt. Gently fold the dry mixture into the aerated egg mixture in thirds using a spatula, keeping as much air as possible.

Add walnuts and butter: Fold in the ground walnuts and vanilla extract. Drizzle the cooled melted butter around the bowl and fold gently until incorporated.

Add blueberries: Toss blueberries lightly with a teaspoon of flour (from the measured flour) to prevent sinking, then fold them gently into the batter.

Bake: Pour batter into prepared pan and smooth the top. Bake 18–22 minutes or until a toothpick inserted in the center comes out clean and the top is lightly golden. Avoid overbaking to keep sponge moist.

Cool: Remove from oven, cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Trim or level the cake if needed to fit your mold or ring for assembly.

Make dough: In a bowl, rub the cold cubed butter into the flour, confectioners' sugar, lime zest and salt until the mixture resembles coarse crumbs. Alternatively pulse briefly in a food processor. Add the egg yolk and melted white chocolate and mix just until the dough comes together. Do not overwork.

Chill and roll: Shape dough into a disk, wrap in plastic, and chill for at least 30 minutes. Preheat oven to 170°C (340°F). Roll dough between parchment to 3–4 mm thick and cut into desired shapes or into a disk that will layer under the cake. Place on a baking sheet lined with parchment.

Bake: Bake for 10–12 minutes until edges are lightly golden. Cool completely on a rack. If making decorative sable pieces, you can pipe melted white chocolate and lime zest over cooled sablés for extra white-chocolate-lime flavor.

Bloom gelatin: Sprinkle gelatin over the 30 ml cold water and let bloom 5–10 minutes.

Make lime custard: In a small saucepan, whisk together egg yolks and sugar until smooth. Stir in lime juice and lime zest. Cook over low–medium heat, stirring constantly, until the mixture thickens slightly and coats the back of a spoon (do not boil). Remove from heat.

Add gelatin: Warm the bloomed gelatin briefly in the microwave or over a water bath just until melted. Whisk the melted gelatin into the warm lime custard until fully combined and smooth. Allow mixture to cool to near room temperature but not set.

Whip cream and fold: Whip the 300 ml cold cream to soft peaks. Fold one-third of whipped cream into the cooled lime custard to lighten it, then fold in remaining cream gently until homogeneous. Keep chilled until assembly.

Bloom gelatin: Sprinkle gelatin over 20 ml cold water and let bloom 5–10 minutes.

Warm milk and yolks: In a small saucepan, whisk egg yolks with the milk. Warm gently over medium-low heat, stirring constantly, until the mixture thickens slightly (do not scramble eggs or boil). Remove from heat.

Melt chocolate: Place chopped white chocolate in a heatproof bowl. Pour the warm milk/yolk mixture over the chocolate and let sit 1 minute to melt, then whisk until smooth and glossy.

Add gelatin and cool: Warm the bloomed gelatin until melted and whisk into the white chocolate mixture. Allow to cool to near room temperature but not set.

Whip cream and combine: Whip the 350 ml cold cream to soft peaks. Fold a small portion of whipped cream into the white chocolate mixture to loosen, then fold in the remainder gently until smooth and airy. Chill briefly if needed before assembly.

Prepare mold/ring: Use a cake ring or springform with acetate strip if available. Place a layer of blueberry walnut sponge cake at the bottom of the ring. If desired, brush a thin layer of warmed blueberry jam onto the sponge to add shine and extra fruit flavor.

First mousse layer - white chocolate: Pipe or spoon a layer (about one-third) of white chocolate mousse onto the sponge, smoothing the top. Chill in freezer or fridge 10–15 minutes to set slightly so layers remain distinct.

Second layer - lime mousse: Gently spoon or pipe the lime mousse over the slightly set white chocolate layer, smoothing carefully to avoid mixing. Chill another 15–20 minutes to firm up.

Final layer - white chocolate mousse: Top with remaining white chocolate mousse, smooth carefully. Tap the ring gently on the counter to release trapped air and level the surface. Chill covered at least 4 hours or overnight to fully set (or 1–2 hours in freezer for faster setting).

Unmold and decorate: Remove cake from ring, peel off acetate. Place a baked white chocolate lime sablé on top or alongside as decoration. Garnish with toasted walnut pieces, fresh blueberries and extra lime zest. Optionally drizzle melted white chocolate over the top or paint small dots of thin blueberry jam for contrast.

Serve: Slice with a hot, dry knife (dip in hot water and wipe between slices) for clean layers. Serve chilled.